Method of making fluorine



Feb. 26 1924.

F.'c. MATHl-:Rs-

METHOD 0F MAKING -FLUORINE Filed June 30. 19,19

NVENTOR c. mrnnss, or BLooMiNG'roN, INDIANA.

" me .rinomata Application med :iuue 30,

To all whom t may camera.'

Beit lmown that I, FRANK'C. MATHERS, a citizen ,of'the United States, residing at- Bloomington, in the county of Monroe and State of Indiana, have invented certain new and useful Improvements in Methods of MakingFluorine, of-which the following is a specification.

This invention relates toa pf Aroducing fluorine. ne of the objects of this ,invention is'to provide an eiiicient method and apparatus novel method .for producing fluorine in large quantities.

Another object `of this invention is to pro- -vide a method by which the cost of produc-` ing luorine isreduced considerably.

In the former processes of making luorine,

electrolytical methods have been .employed but the cost of producing theiiuorine has rendered production on any large scale almost prohibitive; also, no ellicient method has heretofore been used for producing large quantities of fluorine cna satisfactory basis.

My invention overcomes the diiiiculties incident to the prior processes for generating fluorine and enables the substance on a large scale.

Reference isl to be had to the accompanying drawing wherein is shown a cross section of an apparatus which may be used to carry out my invention. .The lapparatus consists of a vessel (1) containing the electrolyte (2) and supported upon standards (3). The electrolyte is heated by means of the burners (4). A diaphragm (5) extends into the vessel (1) and reaches below the surface of the electrolyte (2). Located-centrally within the diaphragm (5) is the anode (6), the lowerv end of which projects into the electrolyte and the upper` end is connected to a conductor (7) in electrical ccntact with the positive terminal (8) of the source of electrolyzing current. The cathode (9) extends into the electrolyte and is connected to the negative terminal (10) of the electrolyzing current.

It is necessary that the anode (6) be inl sulated and kept from electrical contact with the diaphragm (5), the vessel (1) and the cathode (9). This is accomplished by placing' late (11) which 'oins the conductor -(7), wit terminal (8), etween insulating These blocks are blocks (12) land (13).

preferably made of fluorite. The plate (11) and blocks of uorite are held in position by means of the' clamp (14) fand screw (15) production of this 1919. Serial No. 307,674.

.- By electrolyzing the electrolyte (2), luorine is evolved at the anode (6) and passes out through the exit (16).

'The preferred form of electrolytewhich ll use is 'acid potassium fluoride, but it should be understood that other luorides or comounds of fluorine or mixtures thereof may used which are not 'attacked by iluorine and which melt at a temperature at -which the graphite anode vand the containing vessel are not seriously attacked by fluorine. Anhydrous potassium acid fluoride melts at approximately 220. C. and at this temperature decomposes but slightly. The vessel 1 may be made of copper,.in which event the cathode (9) may be dispensed with, the vessel" (1) serving as a cathode. The diaphragm (5) is made preferably of copper. It should be understood that other material vthan copper may be used for the vessel (1),

and in such cases a special cathode (9), made of a suitable material such as copper is einployed.

A satisfactoryV current density has been 30 found to be 10 amperes per square decimeter, and an E. M. F. of 12 to 15 volts.

Th'ebath should not be heated so low that the electrolyte will be too viscous, neither should it be heated so highly that HF will distill olf too rapidly. At higer temperatures the conductivity of tlie bath is increased appreciably, but the loss of HF offsets this advantage.

' The present invention is not limited to the specific details set forth in the foregoing examples which should be construed as illustrative and not by way of limitation, and in v view ofthe numerous modifications which may be e'ected therein without vdeparting from the spirit and scope of this invention,

it is desired that only such limitations be imposed as are indicated in the appended I claim as my invention: 1. In a method of making iluorine, electroly'zing a fused acid iiuoride with an anode y, of hard carbonaceous material and collect- -ing the evolved liuorine.

trolyzing a fused .acid alkali metal Huoride with! a graphite anode and collecting the evolved fluorine.

5. A process comprising. the electrolysisl with an anode of hard carbonaceous material and a copper cathode of an acid alkali metal fluoride inv a state of fusion and collecting the evolved fluorine.

6. A process comprising the electrolysis with a graphite anode and a copper cathode of an acid alkali metal fluoride in a state of fusion and collecting the evolved fiuorine.

7. A process comprising the electrolysis with an anode of hard carbonaceous material of fused potassium acid fluoride and collecting the evolved iluoriinee megas@ an anode of hard carbonaceous material anda" current having an electromotive force of approximately 12-15 volts and collecting the evolved luorine.

10. In a process of making'iiuorine, electrolyzing a fused fluorine compound with a graphite anode and a current having an electromotive force of approximately 12-15 volts and collecting the evolved uorine.

' FRANK C. MATHERS. 

